How this animation works
Scroll-scrubbed frame-sequence background.
- Trigger
- page scroll — overall scroll progress maps directly to a frame index, so scrolling forward plays the sequence and scrolling back rewinds it, like scrubbing a video with the scrollbar.
- Motion
- a fixed full-viewport canvas draws a preloaded image sequence (~144 AVIF frames) behind the page while normal content sections scroll over it; HUD elements (frame counters, progress rails, live stats) update from the same progress value.
